The data on these three subjects in this report arc for employed persons and refer to the job held during the week for which employment status was reported. For persons employed at two or more jobs, the data refer to the job at which the person worked the greatest number of hours. The occupation and industry statistics presented here are based on the detailed systems developed for the 1960 Census; see 1960 Classified Index of Occupations and Industries, Government Printing Office, Washington 25, D.C.